You have not stated which version of PD you have, if you have PD5, download to you desktop first, then import into PD. A DVD is basically a finished product, and will not import via capture, at least thats my experience. This problem has been reported many times before in this forum.
Anyway, give it a try and report back
Regards
Robert
Intel i7 930, 16GB ram, Radeon HD 5770 1Gb,Ver. 14.12 Win7 64 bit
Intel i7 7700 HQ, 16 GB ram Nvidia GTX 1050Ti 4GB dual drives 1 TB SSD + 1 TB HDD Win 10
PDtoots